Electric heater



F. C. HUGHES.

ELECTRIC HEATER.

APPLICATION nuzo OCT. 9. 1920.

Patented Dec. 6, 1921.

H. w .w. .1,

' UNITED sm es PATENT'OFFICE.

FRANK G. HUGHES, OF CHICAGO, ILLINOIS, ASSIGNOR F ONE-HALF T0 NOEL CARRICO,

' OF SIDNEY, MONTANA.

ELECTRIC HEATER.

Specification of Letters Patent.

Patented Dec. 6, 1921.

" To all whom it may concern:

electric heaters and more Be it known that I, FRANK (J. Huenns, a

citizen of the United States, residing at 5660 West Taylor St., Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Electric Heaters, of which the following is a specification.

This invention relates to improvements in especially to that type of heater equipped with a substantially bare resistance element usually made of a wire of an alloy of nickel and chromium formed into a helix or spiral with convolutions. In the form of heaters to whichthis invention relates the resistance element is usually supported by an electrically nonconductive support, 'being laid in grooves formed therein. The grooves within which the resistance element lies maybe formed in parallel lines, in the shape of a spiral, or in any other desired formation.

. n the type of heaters referred to, the resistance element is usually fastened in the groove in the supporting plate merely at its two ends, or else at lnfrequent intervals throughout its length. Where not fastened directly to the supporting plate, the reslstance element merely lies or rests in the groove. In heaters so constructed, the heat from the resistance element is radiated to the surrounding air and thus conducted to the utensil or other ultimate object desired to be heated. Some of the heat radiated from the element also heats the supporting plate which in turn radiates the heat from the device. In the devices referredto, heretofore used, however, the amount of heat taken from the resistance element to the supporting plate and radiated therefrom is relatively small because of the fact that there is no good heat conducting connection be-- tween the element and the supporting plate. Most of the heat from theheater is obtained directly from the resistance element itself. In my improved heater, I attach the resistance element throughout its entire length to the supporting plate b an electrically non conductive and therma ly conductive cement. With this construction,

1 relatively larger amount of heat will be conducted by means of the attaching cement directly from the resistance element to the su portlng plate from which it is radiated to t e cooking utensil or other ultimate object to be it is obvious, that a .dicated by 12.

heated. By this construction, the resistance element itself is maintained at a lower temperature with a consequent prolongation of its life. I

Another advantage in connecting the reslstance element to the supporting plate throughout substantially its entire length. 1s to prevent it from being distorted or broken. In heaterswhere it is joined to the supporting plate merely at its ends, or at infrequent intervals, those portions not joined, are llkelfy to be displaced, liftedout, or removed rom the groove and consequently subjected to breakage or injury.

' In that form of device embodying the features of my invention shown in the accompanying drawings, Figure 1 is a top plan v1ew of a portion of a supporting plate provided with parallel grooves adapted to receive a resistance element, showing one of the grooveswith the resistance element removed, Fig. 2 is a view taken as indicated by the line 2 of Fig. 1, and Fig. 3 is a view taken as indicated by the line 3 of Fig. 1.

As shown in said drawings, 5 represents a supporting plate made of porcelain, lava, or other suitable electrically non-conductive material having formed in its upper surface the parallel grooves 6, 6 separated by the projecting fins 7 8 indicates a resistance element ma e of a. wire formed from a suitable alloy of nickel and chromium, or other suitable resistance material, and bent into the form of a helix. My improved heater is made by puttin in the grooves 6 a small amount of pow ered borax as indicated by 10. The resistance element 8 is then laid in the groove with the bottoms of its convolutions resting in the powdered borax. If desired, the resistance element may be put in place first and the. powdered borax then poured in. The resistanceelement is then 'convolutions of the resistance element to the bottoms of the grooves 6. A portion of the resistance element is shown so cemented to the supporting plate in the drawings, in which the sticky glassy substance formedby melting the borax, as described above, is in- The attachment of the resistance element to the supportin plate is clearly shown in Fig. 3, from WhlOhit will borax for cementing the element to the supporting plate, it is to be understood that I am not to be limited to the use of this substance alone, since there are many other substances which will serve the purpose. Any

- electrically non-conductive substance which will conduct a portion of the heat from the element to the supporting plate may be used for attaching the element to the supporting plate, without detracting from the spirit of this invention.

Although I have shown the use of a resistance element formed in the shape of a helix and composed of an alloy of nickel and chromium, it is to be understood that I am not to be limited to'the use of a resistance element formed of such a substance, or so shaped. In the use of my invention, a resistance element of any other desired shape or composition may be employed without detracting from'its spirit.

Although I have shown the use ofa support formed of electrically non-conductive material, it is obvious that it need'not necessarily be electrically non-conductive. By

the heat from the element to the by Letters Patent is:

ductive cement formed from the borax, a

support may be used which is electrically conductive.

While I have shown and described certain embodiments of my invention, it is to 'be understood that it' 1s capable of many modifications. Changes therefore in the construction and arrangement may be made without-departing from the spirit and scope of the, invention as disclosed in the appended claims, in which it is my intention to claim all :novelty inherent in my invention 1 as broadly as possible in view of the prior art. What I claim as new, and desire to secure 1. In an electric heater, a'substantially bare resistance element attached to a support by an electrically non-conductive and thermally conductive cement whereby a portion of the heat from the element is'conducted to the support and radiated therefrom.

2. In an electric heater, a substantially bare resistance element attached to an electrically non-conductive support by an.elec-' trically non-conductive and thermally conductive cement whereby a portion of the heat from the-element is conducted to the support and radiated therefrom.

In witness whereof, I have hereunto set my. hand and seal this 5th day of October 1920.

FRANK C. HUGHES. [L. s.] 

